Molding flask



March l11;, 1930. J. R. swlFT l 1,751,369

MOLDING FLASK Filed July l, 1927 Patented Mar.v 1s, 1930 f JUSTIN fia. SWIFT, lon 'nvnivsron 'l inniirois,` Assieavon To l TiynsUrnnIoR l COMPANY OEGHlQAGrO, 1.SLLI1\1oIs, acoRPonaTIoNgoFILLINOIS f nonnina'` rnns i i t :Appliqatrienwlea July' 1, 1927; r"'seriaino'. 2fo2,925."y

. My invention relates to the art offvmolding, and particularly to apparatus adapted for use in producing molded rubber characters such as rubber stamps. l y n According to the known practice, a shallow flask is provided'within which isplaced a plastic composition in which impressions are made ywhile still plastic, thematerial being thereafter permittedto harden and to act as a matrix for the-subsequent productionV of one or more specimens of the objectY to be reproduced. In order to hasten the'hardening or setting of the plastic material, it is and has'been customary tol place the flask and contained material in a dryer and apply heat thereto for a considerableperiod of time. In the use ofV the apparatus heretofore known,

experience has shown that the drying time Y can not be shortened by increasing the degree of heatrfor the reason Vthat any substantial increase in the applied heat resulted in the formation of steamv or other gases within 4the plastic material, the escape of which serves Vto disrupt the surface and toV destroy the im-y pressions theretofore made in the plastic may terial.

An object of my invention is to provide apparatus so constructed as to enable a much greater degree of heat to'be applied inthe drying operation and thereby to'greatly re` duce the drying time. Thevresult is secured by providing in the floor of the iask a multiplicity ofequally spaced apertures and combining with the flask a base plate having a multiplicity of equally spaced upwardly projeoting pegs of substantially the size of the apertures in the floor of the flask. Preferably the base plate is of a size equal to that of the largest flask that will be employed. Byreason of the arrangement of the pegs the base plate will, therefore, permit of the combination therewith of flasks of any size smaller than that of the largest size.

In operation, the flask is placed over the base plate, the pegs serving'toclose the openings in the floor ofthe flask." The flask is then filled-with the plastic material and the impressions made in the material. There-'vY n l I I t also shown fin position :on the .peg plate .inl the after, the flask vis lifted from `the'base plate, leaving the multiplicity of vent hole/ts in the floor. ,The'iask and contained' materialis athen placedlinth'e dryin'govenand afhigh Y V.degree of A.heat applied thereto.: kThe :vent

lholes enableothe escape of the Agases from the ymaterial:)and preventdisruption of the-'walls v55 e t ofthe mold i` f Y i 1 f, The invention. willl be more readilyunder-,Y

lstood by reference to the accompanying draw-` ings', in whichyir v -V Fig. 1' is a planview of ra base VYplate `and ,60 .mold constructed' in, accordance with ini -ventio11; i f Y' "i i' equally spacedpegs, .12, projecting front'the 70 madewhilethe material is still plastic. It will be noted that the pegs V12 project entire-y ly'through theffloo'r, 13. of the'flasksfand into the. cavity 15;-As a; result whenthe flask and peg plateare separated,-a multitude'of ventholes are provided through the floorV of the 'flask and extendinginto thevplasii ma- `terial inthe forml lof small recesses or inde'n tations-.` This permits'the escape.ofsteamv oi* thergaseslthatf may bedriven"outfby.y

:of heat'on the plastic`substance. [A151 largest ,flask that will be employed. A For ,eX- ample, in Fig. 1, a large 'flask' is indicatedbly vthe/,dotted lines 17,' Vvofi-'such sizel that lall, ,ofthe pound, dried;

" diie'rentsiaes, sash tier y H Y :multirlleitr of serially snarled through epee Whatever the length and breadth thereof,

may be positioned on the peg plate. Y

In the carrying out of the process, a flask such as indicated in the drawings is placed on the peg plate and the plastic material 16 placed-in the flask. The impressions are then made.in the plastic material and the flask removed from-the peg plate, In the laststepi the flask iS placed .in a dryer Where it'S subjected relatively high degree 0f heat. The lfirst action ofthe heat is to form a crust over the top exterior surface. before, the interior has been relieved of its'gases.

VHowever, the lower surfaee of; the pltlll terialrnay still be permeated and the gases vmay easily escape through the vent holes formed bythe Withdrawal of thepegs from lthe opening.V This is clearly shown in Fig. 3. VAfter the plastic` material has been dried and is hard, itis utilized as a matrix for casting rubber thereon, usually for the production of rubber type, rubber stamps, etc'. 1 f Y Thenumber, size and distributionof the vent holes is a matterv of importance and the essentials-Were determined only after long and careful experiment. In the const-ruction. illustrated, the openings are 1/8,

these dimensions are not essential, they are recommended-.for successful practice. v

` Obviously modifications 'may be made in i; the construction shown, and I do not Wish to be limited except as indicated in the appended claims;

- j I claim:

, 1. In combination, arbase plate of' a size equal tothe sizeof thev'largest flask that is to be employed, said plate having a multiplicity of equallyV spaced Vertical pegs in its upper surface, and a plurality of flasks of different sizes, each flask 'having a multiplicity of equally spad holes in its floor, any one of said flasks being adapted to be accommodated on saidbase plate with the pegs filling said holes during the placing of the -nolding cem.- pund in the flask and the taking vof the im.-

Peills h@ .Compound and .to be sepaplate betere the com? lated frere lease In apparatusfer melding .rubber type;

3. Molding apparatus of the class described, comprising in combination, a flask a 4separated before the material is placed in a dryer. Y

.In testimony whereof I have affixed my Signature JUsTrN e. SWIFT.

i y diameter, arranged on 141/27 centers.l Ihe pegs are of suchlengththat their upper ends Y project 31g into the molding space. While the eembnatien oa plurality ef flasks. ef]

gY in its Heer a ser@ a has@ plate having mltt of i, LI sp. 'ed reread-Pegs .or puls, adapted t9 @lr pic @ette as' die jan 

